1. Field of the Invention
The present invention relates to a compound and a method for producing the same, and a method for producing oseltamivir phosphate.
2. Description of the Related Art
There is concern that mutation of an avian influenza virus results in a pandemic of new influenza, for example, H5N1 to cause a number of deaths. Oseltamivir phosphate (trade name “Tamiflu”), which is an antiviral drug, is known to exhibit a remarkable response to new influenza, and the state institutions increasingly stockpile such a drug for infection prevention. Therefore, the demand for oseltamivir phosphate is rapidly increased across the world and there is a demand for developing a measure for inexpensively supplying oseltamivir phosphate in a large amount.
As a method for synthesizing oseltamivir phosphate, a method of using shikimic acid as a starting material is known (see, for example, J. Am. Chem. Soc., 119, 681, 1997).
However, shikimic acid is prepared by extraction or purification from Illicium verum fruits (star anise), or via fermentation from D-glucose by E. coli, and there is a problem that such processes are time-consuming and costly. In addition, it is sometimes difficult to supply plant materials such as Illicium verum fruits stably. Accordingly, there is a demand for developing a measure for efficiently chemically synthesizing oseltamivir phosphate from an easily available raw material compound.
For example, a method for synthesizing oseltamivir phosphate from 1,3-butadiene and acrylic acid, and an intermediate in the synthesis method have been proposed (see, for example, J. Am. Chem. Soc., 128, 6310, 2006).
In addition, another method for synthesizing an intermediate leading to the synthesis of oseltamivir phosphate described in J. Am. Chem. Soc., 128, 6310, 2006, which is a diene compound (compound A illustrated in FIG. 1), has been proposed (see, for example, Org. Let., 2008, 10, 815 and FIG. 1).
However, such techniques proposed cannot be said to be sufficient from industrial aspect, because there are problems that, for example, the synthesized product is a racemic form, and a thiol compound having a high toxicity is stoichiometrically used.
Accordingly, there is currently a demand for providing an intermediate useful for industrially producing oseltamivir phosphate.